14:440:127– Introduction to Computers for Engineers
Notes for Lecture 1
Rutgers University, Fall 2008
Instructor Blase E. Ur
0.1 Intro to the Matlab Environment
0.1.1 What Is Matlab?
Matlab (”MATrix LABoratory”) is a software package (and accompanying programming language)
that simpliﬁes many operations in numerical methods, matrix manipulation/linear algebra, and
other tasks engineers will often want to accomplish. The Matlab language shares common ideas
(i.e.
for loops, if statements
) with other languages like Java, C++, and Python. Matlab was chosen
for this class because of its use in industry, elaborate Matrix manipulation functionality, tools for
eﬃcient graphing/plotting, implementation of numerical algorithms, and specialized toolkits.
0.1.2 Matlab Windows
Generally, the window on the righthand side of the Matlab screen is the command window. The
command window allows you to type in Matlab code one line at a time. This can be good if you
want to test out commands or do quick calculations. However, this can be bad if you have a very
complicated set of calculations or tests you wish to complete.
The window on the bottom left is the command history, which lets you see all of the commands
you’ve typed into the command window.
To the top left, you have a list of ﬁles in the current working directory, which could be useful
if you’re working on a really big project.
0.1.3 Basic Math Operations
First, we’ll try typing in mathematical expressions:
5+5
ans=10
3^2
ans=9
5*5
ans=25
Let’s say we make a mistake and instead wanted to type in 5*55 rather than 5*5. Conveniently,
you can use the Up Key in the command window to cycle through your previous commands. This
lets you repeat commands, but also lets you make small edits (which is very convenient).
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View Full Document0.1.4 Setting Variables
Matlab lets you save values (or the result of expressions) in variables. Variable names must start
with a letter, contain only letters/numbers/underscores, and are case sensitive (i.e. X is diﬀerent
than x). The variable name should always be on the left side of the equals sign, and the value you
wish to store in that variable should be on the right.
Thus, you can type all of the following:
X = 5
X = 5
X = 32 + 5
X = 37
WhenIAddNumbersIGet = 43+34
WhenIAddNumbersIGet = 77
However, the following examples don’t work:
1stNumber = 1 (Variable name must start with a letter)
5 = x (the variable must be on the left side)
Super! = 4 (The exclamation point is not allowed)
0.1.5 Semicolon, Disp
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 Fall '08
 Finch
 matlab, Equals sign, command window

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